Charlie Peters is a student at the Institute, whom Reynie, Kate, Sticky, and Constance meet in The Mysterious Benedict Society. He was a Messenger, and was rumored to be graduating on the day the Society encountered him.
The Society sees Charlie being accompanied by S.Q. Pedalian in a hallway one day while at the Institute. Hoping to gain some insight into the role of the Messengers, and how they are helping Mr. Curtain, the children decide to take a risk and talk to him. Kate distracts S.Q. by running towards him and deliberately taking an extremely dramatic fall, while the other Society members approach Charlie. Upon being asked what he did as a Messenger, Charlie gives them obscure answers and repeats multiple times that he "can't say" what he was doing. S.Q. orders them away after helping Kate up, and the group leaves without any immediate information. However, Reynie later develops the theory that Mr. Curtain is taking memories from various people, and uses Charlie's confusion during their encounter to support his claim. Charlie never reappears in the books after he speaks to the Society.